Processes may be used for making reinforcements including chopped fiber strands, fiber strand rovings and yarn, chopped strand mat, nonwoven fibrous mats, woven fabrics and scrims. Reinforcements may be used with plastics to strengthen and stabilize plastic composites. Processes may also be used for making flakes, like glass flakes, and filler and pigment particles for stabilizing and/or coloring pigments for use in plastics to, texture, stabilize and color plastic composite parts and products. Prepregs may be made either in sheets, bulk slugs, preformed shapes, etc. containing one or more monomers with or without reinforcements and/or flakes and/or filler and/or pigment particles and to keep the prepregs cool, below the polymerization temperature of the monomer(s) until the desired time to form and/or to heat the monomer(s) to polymerize and form a plastic composite.
Forming processes may be used to form small to large and/or structural glass fiber reinforced and/or stabilized and/or colored plastic composite parts or products containing a thermoplastic polymer or a thermoset polymer, or a combination of the two, and one or more of these containing fibrous reinforcements, filler and/or pigment include matched metal die molding, hydrostatic molding, vacuum bag molding, injection molding, resin transfer molding (RTM), reaction injection molding (RIM), vacuum resin transfer transfer molding (VARTM) and other molding techniques.
As the new CAFÉ´ gas mileage standards introduced, there is a larger than ever need for lighter weight vehicle parts that thermoplastic and reinforced thermoplastic (TPFRC) could satisfy, because TPFRC scrap is recyclable. The thermoplastic polymers copolymers or homopolymers may be melted and reclaimed and ground thermoplastic TPFRC may be used in thermoplastic forming processes including injection molding, extrusion, etc. Thus, there is a large need for TPFRC parts like the thermoset plastic reinforced (TSFRC) parts and products made using thermoset processes including RIM, SRIM, RTM, VARTM, LFI (long fiber injection molding), SMC, BMC, Currently, such tendency to form branching and/or cross-linking polymerization in these processes while in the extruder and/or in the injection molding system prior to the mold when using reactive materials causes increases in viscosity and shear resistance that is extremely costly if not prohibitive to the use of such reactive materials in these processes. If ways could be found to polymerize and form the thermoplastic polymers, copolymers and homopolymers in situ surrounding the fiber reinforcements, filler and/or pigment in molds of processes, it would be a valuable advancement.
Low viscosity caprolactam monomers, one containing an activator and another mixture containing a caprolactam monomer and a catalyst may be cast by mixing the two very low viscosity mixtures together prior to casting. However, this mixture should be kept to less than about 100° C. to prevent rapid polymerization. Following casting, the cast mixture is heated in the mold to cause anionic polymerization of the monomer to produce a polyamide. However, this method is not practical for most vehicle and large parts and many other current thermoset parts because of the relatively low temperature limitation and the time delays that are caused in the forming and polymerizing cycle. If TPFRC is to replace metals or TSFRC substantially in the automotive industry and elsewhere, economical method(s) need to be found that will produce such automotive parts of equal or superior performance at competitive costs with metal and TSFRC parts now in use.